The objective of this project are to obtain an understanding of the nature and function of membranes. Oxidative phosphorylation, electron transport and active transport of amino acids, are all membrane related phenomena which require specific spatial orientation of the respiratory carriers and transport binding-carrier proteins in order to function. Studies will be conducted to elucidate the carriers involved, their topology or location in or on the membrane, as well as the underlying driving force involved. A comparison of the bioenergetic driving force for oxidative phosphorylation and active transport of amino acids (proton gradient, membrane potential or both) will be studied with bacterial membrane preparations from M. phlei, which differ in vectorial orientation. Further insight into the bioenergetic mechanism involved with active transport of amino acids may be obtained from the model proteoliposomal system containing the purified "binding"-carrier protein for proline transport. The physicochemical properties of the purified carrier protein will also be studied. In addition, studies will be undertaken to determine the nature and sequences of the respiratory carriers in order to fully characterize the respiratory chain in M. phlei. These studies of membrane-related phenomena will provide insight into the broader questions of the nature, topology of membrane protein, conformational changes and functional aspects of membranes.